The present invention relates to a concave part cover for covering a concave part such as a slot or a hole formed in a machine tool.
Various kinds of slot covers for covering slots formed in machine tools have been suggested.
For example, Japanese Patent Laid-Open (Kokai) Publication No. SHO 57-178639 discloses a T-slot guard that should be used for such machine tools as milling machines, drilling machines, shaping machines, planing machines, and horizontal boring machines, and that comprises a flat top web with a hole punched therein, and two parallel guiding legs which extend downwards from the top web.
Moreover, Japanese Design Registration No. 583836 suggests a machine tool table slot cover that is used to cover a slot in a machine tool table and to prevent, for example, tools or chips generated during machining from falling into the slot. This machine tool table slot cover comprises: a top plate for covering the slot; and a pair of legs mounted perpendicularly to the top plate. Concerning the slot cover, the top plate and each leg form an angle of approximately 90 degrees. The lower parts of the legs project slightly outwards.
This machine tool table slot cover described in the above-mentioned Design Registration is used to seal (or cover) a slot with its top plate by inserting the legs into the slot. When the legs of the machine tool table slot cover are inserted into the slot, projections formed at the top ends of the legs are caused to contact the side walls of the slot, thereby securing the slot cover in the slot.
However, regarding the T-slot guard and the slot cover described in the above-mentioned publications, since the guiding legs are mounted perpendicularly to the top web (or top plate), it is difficult to make the guiding legs fit in the slot with width tolerances. Accordingly, when the T-slot guard or the slot cover is mounted in a slot having a width of a large tolerance, there is a possibility that the T-slot guard or the slot cover may not partly or sometimes fit securely in the slot. Moreover, when the tolerance for the dimensional accuracy of the width is large when manufacturing the T-slot guard or the slot cover, there is a possibility that the T-slot guard or the slot cover may not partly or sometimes fit securely in the slot.